The present invention relates to a separated type air conditioner having an outdoor unit connected to at least one indoor unit by a chilled water circulating system, and more particularly relates to such a separated type air conditioner in which an evaporative condensing apparatus is used in the outdoor unit to greatly improve the cooling efficiency therefore.
In a conventional separated type air conditioner, a condenser and an evaporator of a cooling medium system are separately installed in an outdoor unit and an indoor unit, therefore a long distance piping system of cooling medium is needed between the outdoor unit and the indoor unit for cooling medium circulating. However, there will be several disadvantages occurred, a large amount of cooling capability wasted in the long distance medium pipe due to that the medium is performed of low special heat and the pipes are exposed in the open air of a hot environment, further, the longer pipe of cooling medium is used, the higher compressing pressure of the medium compressor is needed, the power consumption then will be highly increased, further more, a long distance piping of cooling medium exposed in open air has the weakness of leakage due to a weather changing or an accident, it will seriously pollutes the environment.
Theoretically, during the condensing process of cooling medium in the condensing apparatus, the medium is liquidized due to a temperature dropping by a cooling system under a certain high pressure delivered by a compressor, in which, the lower temperature can be reached, the lower relative critical pressure is needed and then a low pressure compressor can be employed for energy saving. FIG. 15 shows a liquid-gas curve obtained form R-22 cooling medium. As indicated the cooling medium can easily be condensed with a low relative pressure when at a low temperature, for example: when at 45xc2x0 C. as point C of the curve, which is almost a lowest temperature that a conventional condensing unit can reach to, in which the relative critical pressure needed for condensing is about 18 kg/cm2, if the temperature can be dropped to 30xc2x0 C. as point B, by a high efficient cooling system the relative critical pressure needed for condensing will be drastically reduced to 12.27 kg/cm2. Therefore, the energy efficiency ratio (E.E.R.) of an air conditioner is directly proportion to the efficiency of the cooling system used in the condensing unit.
An evaporative type condensing apparatus of an air conditioner dissipates heat by means of evaporation of water which is sprayed on to the surface of the medium coil. Theoretically one liter of water absorbs about 539 Kcal evaporating latent heat when evaporated. Therefore the heat dissipation effect of an evaporative type is much better than an air cooling type or a water cooling type. However, when a conventional evaporative type condenser is used, it still has two disadvantages, firstly, the spraying water can not be held on a smooth surface of the bare metal condensing coils for a enough period of time to let the water getting fully evaporated, it will flows off from the medium coils before evaporated,therefore the heat dissipation effect is not fully developed, it can""t do much better than the other two types; secondary, a large water storage means is needed to collect waste water that is not evaporated at the evaporative condensing unit of the air conditioner.
The present invention has been accomplished to provide a separated type air conditioner which eliminates the aforesaid drawbacks.
It is a main object to provide a separated type air conditioner in which the cooling medium system is circulated within the outdoor unit only, and not circulated to indoor unit ,instead, a chilled water circulating system is used to connect from outdoor unit to each of indoor unit for cooling capability transmitting so as to improve the energy saving and environment protecting.
It is another object to provide a separated type air conditioner which an evaporative condensing apparatus is used in the outdoor unit for highly increasing the cooling efficiency to provide an extreme low temperature of the cooling medium there at, in which the relative critical pressure needed to condense the gas state cooling medium into liquid state can be greatly reduced, therefore a comparative low pressure compressor of low power consumption can be employed for energy saving.
According to one expect of the present invention which the evaporating apparatus in the outdoor unit is formed of a medium/water heat exchanger type water chiller in which the cooling medium absorbs heat from water during evaporating so as to produce chilled water thereat; the indoor unit is formed of a water/air heat exchanger type air cooler comprising a plurality of chilled water coils having a plurality of parallel cooling fins perpendicularly to the coil tubes to form a plurality of air gaps there between, a fan system disposed at a front side of the chilled water coils for delivering a current of air passing through the air gaps between the cooling fins and to be cooled therefore; and a water circulating system comprising a water pump disposed in the outdoor unit for operating the system therefore, a piping system including a chilled water delivering piping connected form an outlet pipe fitting of the water chiller of the outdoor unit to an inlet pipe fitting of the air cooler of the indoor unit, and a water feedback piping connected from an outlet pipe fitting of an inlet pipe fitting of the water chiller of outdoor unit.
According to another one aspect of the present invention, the evaporative condensing apparatus of the outdoor unit comprises a plurality of condenser coils and characteristically having a layer of absorptive material covered on the condenser coils, a water supply system having a plurality of water spray tubes and absorptive material covered on the water outlets of the water spray tubes for permitting supplied evaporative water to be evenly smoothly distributed to the absorptive material at the condenser coils, and a control PC board which automatically adjusts an intermittent period of water supplying according to a temperature signal taken from the condensing coil by a thermal sensor, and an electromagnetic valve controlled by the control PC board to let water be delivered intermittently from a water source to the layer of absorptive material of each condenser coil; a compressor of comparative low pressure controlled to provide an adequate pressure for delivering the gas state cooling medium into the condensing unit and to condense the medium into liquid state thereat. And a condenser fan controlled to draw currents of air through gaps in the condenser coils of the evaporative condensing unit in carrying the evaporated moisture and heat away from the evaporative condensing unit.